Of 5,874 billboards found by investigators (owned mostly by Clear Channel Outdoor, CBS Outdoor and Lamar Outdoor), a staggering 1,423 have "observable violations." Mostly graffiti that the multi-billion dollar billboard industry, which has given campaign funds to most Los Angeles elected officials, han't cleaned up. Some billboard violations are troubling:

Luke Zamperini, principal inspector at the Department of Building and Safety, says 44 of the often-huge signs had structural violations - "typically missing edges of the frames surrounding the copy and copy torn loose by winds," and 22 had electrical violations - "typically loose conduit or exposed wiring high up on the structure."

But in an ugly twist for anti-clutter activists, of those 540 signs, the owners of nearly all 540 can cite an obscure law to be grandfathered in as legal. According to California Business and Professions Code section 5216.1"

"... an advertising display is lawfully erected if it has been in existence for a period of five years or longer without the owner having received written notice during that period from a governmental entity stating that the display was not lawfully erected."

In other words, because Los Angeles City Hall years ago failed to get a grip on its thicket of illegal billboards, many can remain in communities tired of what many residents see as visual pollution.

As KCET reports:

"Not all billboards have been matched to a sign company. There are still a lot of gaps to be filled, which is unsurprising given the city's history of letting sign companies play fast and loose with the rules when putting up new billboards."

It's not even known, because the City Council failed to act for so many years, how many of the 540 billboards were unlawfully altered -- doubled or tripled in size, for example -- since they don't have a permit saying what was originally allowed.

The "off-site sign" survey was ordered by a previous Los Angeles City Council way back in 2002.

A majority of the City Council took money from the billboard industry, then ignored their illegal advertising for years.

Most current members of the City Council, a large majority of whom have taken billboard money, failed for years to fund a modest budget to hire a small group of inspectors to pore over old documents and conduct a visual inspection on the streets.

Thanks to the City Council's refusal to act, the Department of Building and Safety took seven years to launch the survey. Amidst mounting criticism of the City Council and Mayor Antonio Villaraigosa from angry activist groups, Building and Safety finally got the billboard inspection job done in 2011.

That was 11 years after the billboard survey was "ordered."

Then, inexplicably, the 2011 Los Angeles billboard survey wasn't released to the public.

Lisa Sedano fought City Hall this year, pressuring them to release the 2011 billboard survey.